I need help on this question in math

The rate of change or essentially the slope is a numerical value that describes the direction and the steepness of the line.
To find the slope, we just need any two points on the line
--> Let's pick (0,2) and (2,6)
The slope's equation = [tex]\frac{y2-y1}{x2-x1}[/tex]
Let's plug the known quantities into the equation
[tex]\frac{y2-y1}{x2-x1}=\frac{6-2}{2-0} =\frac{4}{2} =2[/tex]
Therefore the rate of change is 2 km/trip
Hope that helps!